Inter-annual variability of heavy metals pollution in surface sediments of Jiangsu coastal region, China: Case study of the Dafeng Port

The Jiangsu coastal environment in China is affected by pollution, and the Cu, Pb, Cd, Zn, Cr, As, and Hg concentrations in the surface sediment of Dafeng Port during 2011–2017 were analyzed to determine their contamination and ecological risks. The multi-year average of Zn, Cr, Pb, Cu, As, Cd, and Hg concentrations were 50.10, 40.32, 12.41, 11.76, 8.67, 0.08, and 0.04 mg/kg, respectively, which were generally higher than their background values, except for those of Cu and Cr. The spatial distribution of heavy metals were similar, and the highest concentrations were measured near Dafeng Port and coastal river inlets. The geoaccumulation index generally indicated moderate–low ecological risk, except for Cd. Multivariate statistical analyses showed that Pb, Zn, Cr, As, Hg, Cd, and petroleum were strongly influenced by anthropogenic activities, whereas Cu derived from both natural and anthropogenic sources. This study provides important information for the management of heavy metal contamination. •High heavy metal concentrations occurred near Dafeng Port and coastal river inlets.•Igeo values showed an uncontaminated environment and moderate–low ecological risk.•However, Cd is an important contributor to pollution in and around Dafeng Port.•Pb, Zn, Cr, As, Hg, and Cd had anthropogenic sources, but Cu also had natural sources.•We provide information for the management of heavy metals along the Jiangsu coast.